Tool safety latch



1950 v. N. BUJOLD 2,957,724

TOOL SAFETY LATCH Filed Feb. 3, 1958 2 Sheets-Sheet 1 /.9- E I i4 5 I 44 36 I 5 in 1 46 i 25%!" Z; an I J 47 i I.

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INVENTOR. WHANN Mc MAN/GAL 14/ far/my: for 4,0 1/000/ Oct. 25, 1960 v, BUJOLD 2,957,724

TOOL SAFETY LATCH Filed Feb. 3, 1958 2 Sheets-Sheet 2 V/CTO/F N. BUJOLD, INVENTOR.

WHA/VN 8 MC MAN/6A L If/orrnys fir 150/1540) United States Patent TOOL SAFETY LATCH Victor N. Bujold, Long Beach, Calif., assignor to Web Wilson Oil Tools, Incorporated, Los Angeles, Calrfl, a corporation of California Filed Feb. 3, 1958, Ser. No. 712,750

12 Claims. (Cl. 294-102) The present invention relates generally to a tool or device such as used for handling oil well casing, drill pipe, tubing, and the like, and is more particularly concerned with an improved safety latch mechanism therefor.

The present invention is illustrated in general as being embodied in an elevator tool of the so called side door type such as used for the handling of casing, and which conventionally utilizes a spring biased latch member mounted on a main jaw structure, this latch member being adapted to latchingly engage with a lug on a hinged door comprising a cooperative jaw structure, to retain the jaws in a closed position encircling the casing or like member. In the presently known structures, this door also carries a pivoted swingable handle which normally projects outwardly from the door, so that it may be grasped by an operator and by exerting a generally tangential pull thereon the operator may swing the handle so as to trip the latch and thereafter swing the door to an open position.

It is an object of the present invention to provide a latch locking member on the door structure of a tool such as described herein, which is associated with the handle so that the handle in the latch locking position of the latch lock will normally lie closely against the door structure where it will be out of the way and will not catch on ropes, chains or other such materials as are commonly used around an oil well.

A further object of the invention is to provide a unique latch locking means for tools such as elevators, and the like, having jaw structures, which are so arranged that opening of the jaws under shock and vibration will be prevented.

Another object is to provide in a tool of the herein described type, an improved latch locking mechanism wherein initial movement of an associated jaw operating handle also acts to release the latch lock, and upon further movement of the handle will cam the latch to a released position so that the handle may then be utilized to open the door jaw structure.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanying drawings, which are for illustrative purposes only:

Fig. l is a perspective view of a device embodying a safety latch and actuating mechanism according to the present invention, the jaw structures being shown in pipe encircling position;

Fig. 2 is a similar view showing the door jaw structure in opened position;

Fig. 3 is an enlarged fragmentary view in elevation showing the corporative relationship of the latch, latch lock and handle comprising the present invention;

Fig. 4 is a fragmentary plan view of the parts shown in Fig. 3; and

Fig. 5 is a sectional view showing the interconnection meral 10, adapted to be closed and latched around a.

casing or pipe which is to be suspended or lifted. Basically the structure 10 is composed of a main body 11 which is formed at its ends with extending arm structures 12 and 13 for the connection of suspending cables, links or other means by which the device may be connected with a travelling block. Between these arm structures, the main body is formed with a conventional inner semicylindrical surface 14 which is arranged to be cooperatively associated with a similar surface 15 of a hinged door 16 to encircle the outer surface of the casing, pipe, tube or other member to be handled by the device, when the hinge door is swung to a closed position. The main body and hinge door thus constitute jaw structures which are movable into closed and opened positions with respect to the casing, tube or pipe with which the device is being utilized. a

The main body 11 is provided at one side of the surface 14 with a pair of vertically spaced projecting lugs 17 and 18 which form a support for a vertically extending pivot pin 19 on which there is swingably mounted a latch member, as generally indicated by the numeral 20. As shown in Fig. 3, the latch member is formed with spaced arms 21 and 22, these arms being supported at their inner ends on the pivot pin 19, and at their outermost ends being interconnected by an integrally formed bridging latching bar 23 which is adapted to ride up over a latching lug 24 projecting from the outer free end of the door 16, when the door is swung to closed position. The door 16, as perhaps best shown in Fig. l, is provided with spaced hinge lugs 25 and 26 which are swingable on a pivot pin 27 mounted on the main body 11 on the opposite side of surface 14.

The pivotal movement of the latch member 24 is limited in its latching direction by the engagement of a stop lug 28, Figs. 4 and 5 with a projecting lug 29 on the main body 11. The latch member is normally biased towards latching position by a lat-ch spring 30, as shown in Fig. 3, which is coiled around the pivot pin 19, one end of this spring bearing against an adjacent surface of the main body While the other end bears against a reinforcing bar 31 extending between the arms 21 and 22 of the latch member.

At the outer free end of the door 16 there is provided, adjacent the latching lug, a handle 32 of generally U- shaped construction and having spaced arms 33 and 34 thereof swingably associated at their inner ends with a pivot pin 35 supported in spaced lugs 36 and 37 carried by the door structure. The arms 33 and 34 are reinforced adjacent their pivoted ends by a bracing bar 38. The handle 32 is normally biased in a counterclockwise direction as viewed in Fig. 4, by a spring 39 which is coiled about the pivot pin'35, one end of this spring being anchored in the lug 36, while the other end of the spring bears against the bracing bar 38. This spring acts to normally retain the handle at one limit of its pivotal movement in which the movement is terminated by means of a stop projection 40 extending from the arm 34, when .this stop projection engages against the adjacent sur- 16 to its open and closed position, but also as a camming mechanism for moving the latch 20 to a released position with respect to the latching lug 24. For such purpose, the arm 34 of the handle is constructed with camming edge surfaces 42 and 43 which are adapted to bear against the adjacent surface of the bridging latching bar 23 of the latch member 20 in such a manner that the latch member 20 will be swung to a released position with reference to the latching lug 24, as the handle 32 is pulled away from its normal position in a clockwlse direction as viewed in Fig. 4. The basic principles of operation of the parts thus far described are conventional to the devices heretofore known, and it is in the provision of latch locking mechanism for these parts which constitutes the present invention, and which will now be described in detail.

As: primarily shown in Figs. 3 and 5, the locking mechanism includes an elongate locking bar or lever 44 which is pivoted between its ends upon the pivot pin 35 for swinging movements. The locking bar has its opposite ends 45 and 46 deflected in opposite directions. The locking bar is positioned below the lug 36 and is normally biased in a clockwise direction as shown in Fig. by means of a coil spring 47 on the pivot pin 35, one end of this spring bearing against a projection 48 on the same side of the pivot pin 35 as the end 45 of the bar, while the other end of the spring bears against the bracing bar 38 of the handle structure. The action of this spring is to normally maintain the end 46 of the locking bar in resilient engagement with the bracing bar 38 of the handle, when the handle is in its normal full line position as shown in Fig. 4, in which position the end 45 of the locking bar is positioned in the path of movement of the stop lug 28. With the end 45 of the locking bar thus positioned, the latch member 20 is prevented from movement to an unlatched position with respect to the latching lug 24 of the door 16. However, it will be apparent that by moving the handle 32 away from its normal position in a clockwise direction as viewed in Figs. 4 and 5, the handle and locking bar will be rotated as a unit until the end 45 of the locking bar has cleared the stop lug 28 as indicated by the numeral 45' in Fig. 4. In this position, the end 45 will abut the adjacent surface of the door 16 at a point as indicated by the numeral 49 so that further movement of this end of the locking bar will be terminated and further continued movement of the handle will cause the handle to move independently and relative to the locking bar.

During this continued movement of the handle, the. bracing bar 38 moves away from the end 46 of the looking bar until the handle reaches the position indicated at 32, whereupon the camming edge surface 42 will engage the latch member at a point indicated by the numeral 50. Since the latch member is at this time unlocked by virtue of the end 45 of the locking bar having been previously moved out of the path of the stop lug 28, further movement of the handle will in the position of the handle indicated by the numeral 32" have caused the camming surface 43 to have been brought into engagement with the latching member at a point indicated at 50, thus moving the latch member to a released position 20' with respect to the latching lug 24. The handle may now be manipulated to move the door 16 to an open position.

With the door in open position, release of the handle 32 will permit the springs to restore the handle and locking bar to their normal positions as shown in Fig. 5. In closing the door 16, the bridging latching bar 23 will ride up onto the surface of the latching lug 24 until the bar 23 is able to move over the end of the latching lug. The spring 30, which biases the latch member towards latching position is sufiiciently stronger than the spring 39 so that as the latch moves to latching position, the stop 28 will momentarily rotate the locking bar and handle in a clockwise direction sufficiently to permit the passage of the stop 28, whereupon the handle and locking bar will be biased to their normal locking position, as shown in Fig. 5. The end 45 now prevents movement of the latch member to a released position with respect to the latching lug 24, and opening of the door 16 under vibration and shock conditions will thus be prevented.

Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific form shown or uses mentioned, except to the extent indicated in the appended claims.

I claim:

1. A tool, comprising: a pair of jaw structures having a hinged connection enabling relative swinging thereof to opened and closed positions; a latch member carried by one of said jaw structures and being releasably engageable with the other of said jaw structures in said closed position; latch locking means carried by said other of the jaw structures and mounted thereon for movement to released and locking positions with respect to said latch and acting to oppose disengagement of said latch member in said closed position of the jaw structure; and movable handle means carried by one of said jaw structures operable to initially move said latch locking means to its released position and thereafter move said latch member to a released position.

2. A tool, comprising: a pair of pipe engaging jaw structures having a hinged connection enabling relative swinging movements thereof to opened and closed positions; a latch member carried by one of said jaw structures releasably engageable with the other of said jaw structures in said closed position; a movably mounted locking member biased for movement to a locking position with respect to said latch member in said closed position of the jaw structures; and means for releasing said latch and actuating said jaw structure to opened position including a movably mounted manually operable release member for moving the locking member out of said, locking position, said locking member and release member being carried by the other of said jaw structures.

3. A tool, comprising: a pair of pipe engaging jaws having a hinged connection enabling relative swinging movement of an outer end of one of said jaws to opened and closed positions; a latch member pivotally mounted on the other of said jaws for swinging movement; a latch lug carried by the outer end of said one of said jaws, said lug being engageable by said latch member in the closed position of said jaws; latch locking means carried by said one of said jaws including a relatively movable element; means normally biasing said element into a latch locking position opposing movement of said latch along a path disengaging it with respect to. said lug; and a manually movable part carried by said one of said jaws operable to actuate said element to a position out of said path, whereby said part may be utilized to then move said one of said jaws to place the jaws in opened position.

4. A tool, comprising: a pair of jaw structures having a hinged connection enabling relative swinging thereof to opened and closed positions; a latch member carried by one of said jaw structures and being releasably engageable with the other of said jaw structures in said closed position; latch locking means carried by said other of the jaw structures; a movable handle carried by said other of said jaw structures; a connection between said handle and latch locking means for initially effecting unitary movement of the handle and the latch locking \means to a position wherein the latch locking means is in a non-locking position, and relative movement thereafter; and camming surfaces on said latch member and handle coacting during said relative movement to release the =latch member with respect to said other jaw structure.

5. A latch for a tool for handling casing and the like, said tool having a casing encircling structure with first and second free ends adapted to be latched together when the structure encircles the casing, the combination of: a latch lug carried by one of said free ends; a latch member pivotally carried by the other of said free ends for latchingly engaging the latch lug, when said structure encircles said casing; a movably mounted locking memmer carried by the same free end as said latch lug and having a portion for interlocking engagement with said latch member, when it engages the latch lug, to oppose movement of the latch member out of said engagement; and manually operable means carried by one of said free ends including parts operative with said locking member to'move said portion out of said interlocking engagement, and other parts operative to move said latch member out of its latching engagement with said lug.

6. In a latch for a pipe tool comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said parts, said latch member being pivoted for movement into latching engagement with the latch lug, when said structure encircles the pipe; an actuating handle having a pivot mounting on said one of said parts; locking means including an element mounted on the handle pivot for limited movement into and out of a position opposing pivotal movement of the latch member out of latching engagement with said latch lug; and connection means between said handle and locking means for moving said element into and out of said position in response to movements of said handle.

7. In a latch for a pipe tool, comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said parts mounted for movement to latched and unlatched positions relative to said latch lug, when said structure encircles said pipe; a locking member carried by said one part and supported for limited movement to locked and unlocked positions with respect to said latch member, and normally occupying its locked position opposing movement of said latch member to unlatched position, when said structure encircles said pipe; an actuating handle supported on said one of said parts for limited movement, and for actuating said parts out of a pipe encircling position, when said locking member is in unlocked position; and a connection between said handle and said locking member operable by movement of said handle to actuate said locking member to said unlocked position, whereby said parts are movable out of a pipe encircling position by means of said handle.

8. In a latch for a pipe tool, comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said parts mounted for movement to latched and unlatched positions relative to said latch lug, when said structure encircles said pipe; means biasing said latch member towards latched position; a locking member carried by said one part and supported for limited movement to locked and unlocked positions when said structure encircles said pipe; a handle pivoted on said one of said parts for limited swinging movements; means biasing said handle to a normal position lying closely along side said one of said parts, said handle having a stop en gageable during said biased movement with said locking member so as to move it to a normal locking position opposing movement of said latch member to unlatched position, when said structure encircles said pipe; and means normally biasing said locking member in a direction to maintain it against said stop.

9. In a latch for a pipe tool comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said parts mounted for movement to latched and unlatched positions relative to said lug, when said structure encircles said pipe; a locking member carried by said one part pivotally supported for movement to locked and unlocked positions with respect to said latch member when it is in a latched position; a swingable handle carried by said one part including a stop; spring means biasing said locking member into engagement with said stop, and said handle and locking member as a unit in a direction to position the locking member in said locked position.

10. In a latch for a pipe tool comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said parts mounted for movement to latched and unlatched positions relative to said lug, when said structure encircles said pipe; a pivotally mounted locking member carried by said one part movable to locked and unlocked positions with respect to said latch member when it is in a latched position; a swingable handle carried by said one part including a stop; a spring biasing said locking member into engagement with said stop; and a. spring biasing said handle in a direction to move said handle and lock ing member as a unit and position the locking member in said locked position.

11. In a latch for a pipe tool comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch lug carried by one of said parts; a latch member carried by the other of said part-s mounted for movement to latched and unlatched positions relative to said lug, when said structure encircles said pipe; a handle pivoted on said one part for swinging movement, said handle having a portion forming a stop; locking means carried by said one part including an elongate lever pivoted between its ends for swinging movement, one end of said lever having locked and unlocked positions with respect to said latch member and the other end being positioned adjacent said stop; spring means normally retaining said other end of said lever against said stop; and spring means normally biasing said handle and lever in a direction to position said one end of said lever in its locked position.

12. In a latch for a pipe tool comprising a pipe encircling structure with first and second parts adapted to be latched together when the structure encircles the pipe, the combination of: a latch. lug carried by one of said parts; a latch member carried by the other of said parts mounted for movement to latched and unlatched positions relative to said lug, when said structure encircles said pipe; a handle pivoted on said one part for swinging movement, said handle having a portion forming a stop; locking means carried by said one part including an elongate lever pivoted between its ends for swinging movement, one end of said lever having locked and unlocked positions with respect to said latch member and the other end being positioned adjacent said stop; spring means normally retaining said other end of said lever against said stop; spring means normally biasing said handle and lever in a direction to position said one end of said lever in its locked position, said handle and lever further being movable as a unit to position said one end of said lever in its unlocked position, and said handle thereafter having independent continued movement relative to said lever; and a camming surface on said handle operative during said continued movement to move the unlocked latch member to its unlatched position.

References Cited in the file of this patent UNITED STATES PATENTS 

